The Missouri Thesaurus of Medical Informatics Terminology will fill a gap in the discipline of medical informatics. While there are a number of thesauri which cover many of the aspects of medical informatics, none currently covers the entire discipline. The L tree of MeSH comes closest but since there has been no major revision of that since 1987 there are many terms in the discipline which are not found in this source. Researchers at the School of Library and Informational Science and the Medical Informatics Group of the School of Medicine, both of the University of Missouri-Columbia, have been working on creating a new thesaurus to cover the discipline of medical informatics. To date they have gathered terms from a number of diverse sources, chosen the preferred term for synonyms, chosen the lexical variants when applicable, and reduced an initial vocabulary of more than 5000 terms to a few more than 2000. The purpose of this grant is to produce a complete thesaurus of medical informatics terminology and to make it available to the informatics community both through the INTERNET and in a print format. This grant would allow the researchers to complete the project. Specific objectives to be covered by this grant would be: 1) To complete the refinement of the vocabulary; 2) To create/refine a classification scheme to be used with the vocabulary with an accompanying syndetic structure; 3) To create a computer program which will allow the thesaurus and classification scheme to be used easily and to make this program available via the INTERNET; 4) To test the completed thesaurus by using it to index the items in the 1994 SCAMC Proceedings and the 1995 MEDINFO Proceedings; 5) To obtain the comments of experts in the field of medical informatics as to the appropriateness and completeness of the vocabulary and the ease of use of the electronic version.